1. Field of the Invention
The present invention relates to a gun designed to be used in abrasive blasting applications. More specifically, the present invention is an abrasive blasting gun provided with an adjustable spring biased trigger and provided with a removable nozzle end for ease in replacing the internal plastic tube as it becomes worn due to abrasion from the air/abrasive mixture which flows therethrough.
2. Description of the Related Art
Artistic abrasive blasting is accomplished by an artist who employs an abrasive blasting gun instead of a brush in order to etch artwork in glass or other similar mediums. The artist is able to control the location of the air/abrasive stream flowing out of the gun by simply pointing the gun and pulling the trigger in order to start or stop the flow.
One problem which many abrasive blasting guns have is corrosion of the guns by the air/abrasive mixture. Corrosion to the guns requires constant repair or replacement of abraded components of the guns, and generally the guns must be taken out of service in order to accomplish these repairs or replacements. Guns which do not have straight paths through the guns for the air/abrasive mixture to traverse are particularly susceptible to abrasion at corners or curves created in the air/abrasive flow path. Also, those parts within the gun which function to stop and start the flow of air/abrasive are also particularly susceptible to abrasion.
Another problem with abrasive blasting guns is that most are not easily adjustable in order to function within a wide range of pressures and flow rates of air/abrasive mixtures. It is desirable to be able to operate a gun at air pressures ranging from about three pounds per square inch (psi) to about 50 psi and at abrasive flow rates from about two ounces per minute for shadow etching to about 14 pounds per minute for deep etching.
The present invention addresses these problems by providing an abrasive blasting gun having a flexible tube extending in a straight path through the gun which contains the air/abrasive mixture therein. The gun housing of this invention does not come into contact with the air/abrasive mixture, and therefore, the gun housing does not experience abrasion. The present invention is provided with an adjustable spring biased lever which normally squeezes the flexible tube against an upper pinch point in order to prevent the air/abrasive mixture from flowing through the gun. The lever can be pivoted away from the flexible tube by depressing a trigger provided on the gun, thereby allowing flow of the air/abrasive mixture through the gun to be resumed. The tube is attached to a removable nozzle which can be pulled out of the front of the gun along with the attached tube. Once removed from the gun housing, a worn portion of the tube can be removed and the remaining tube reattached to the nozzle. Once the worn portion has been removed, the nozzle and reattached tube are then returned to the gun housing without ever having to take the gun out of service.
It is one of the objectives of this invention to provide a gun which is not abraded by an air/abrasive mixture flowing therethrough.
It is a further objective of this invention to provide an adjustable and lightweight gun for doing artistic abrasive blasting.
It is still a further objective of this invention to provide a gun which can be easily and quickly serviced without requiring the gun to be disconnected from the source of the air/abrasive mixture.